The present invention relates to a vehicular torque control device and a torque control method for controlling output torque when particularly sudden clutch connection operation or a shift-down of a gear is performed.
In the related art, an engine output control device of a vehicle, such as a car, generally employs a configuration for detecting a slipping state of a driving wheel, initiating control at the moment when the slipping state is generated in the driving wheel, restarting supply of fuel to an engine by releasing a stopped state of the supply of the fuel, reducing an effect of an engine brake by increasing an engine speed, and preventing generation of a slip of the driving wheel.
When a braking force by the engine brake is exerted, the slip at the driving wheel, for example, a rear wheel of a rear wheel driving vehicle, is likely to be generated as a load ratio which acts on the front and rear wheels that support a load of a vehicle body decreases at the rear wheel together with an increase of the load at a front wheel. At this time, in an engine output braking device in the related art, as the control is initiated at the moment when the slipping state is generated at the rear wheel, the supply of the fuel to the engine is restarted, and the braking force by the engine brake is reduced, the vehicle is prevented from being in a serious slipping state.
For example, in Japanese Patent No. 3454011, a braking force control device of a rear wheel driving vehicle which prevents a vehicle from being in a spinning state even when the vehicle is turning in a state where a slip ratio of a rear wheel is excessive on a road surface having a low coefficient of friction, by allowing a yaw moment in an anti-spin direction which is given to the vehicle to have a size which corresponds to the slip ratio of the rear wheel, as a target slip ratio of a turning outer side front wheel is calculated based on the slip ratio of the rear wheel so that the target slip ratio of the turning outer side front wheel increases as the slip ratio of the rear wheel increases, the braking force of the turning outer side front wheel is controlled so that the slip ratio of the turning outer side front wheel becomes the target slip ratio, and the braking force is given to the turning outer side front wheel, is disclosed. In other words, the braking force control device described in Japanese Patent No. 3454011 employs a configuration in which the braking force of the front wheel is controlled so that the slip ratio of the front wheel becomes the target slip ratio after calculating the target slip ratio of the front wheel which is a driven wheel based on the slip ratio of the rear wheel which is a driving wheel, and the control is initiated at the moment when the slipping state is generated at the rear wheel.
However, in a case of a motorcycle, when the slipping state is generated at the rear wheel (driving wheel) as the gear is shifted down and the engine brake is suddenly operated, similarly to the device described in Japanese Patent No. 3454011, in the configuration in which the control is initiated at the moment when the slipping state is generated at the rear wheel (driving wheel), there are many cases where the vehicle body is already in an unstable state and a driver feels an anxiety. For this reason, it is desirable that means which can perform the control before the slipping state is generated at the rear wheel is developed in case of the motorcycle. In particular, during cornering travelling, there are many cases where the motorcycle travels by inclining the vehicle body while reducing the speed in a state where the gear is shifted down and the engine brake is operated. In this case, it is assumed that it becomes too late to initiate the control after detecting the slip ratio of the rear wheel (driving wheel), and in the worst case, there is a problem in terms of safety since a situation where the vehicle is overturned is assumed.